The invention relates to a method and apparatus for controlling a crimping process serving for the connection of a contact with a conductor, wherein a crimping tool of a crimping press is movable from a starting position into a crimping position and subsequently into an end position.
Equipment for producing a crimped connection has become known from U.S. Pat. No. 5,966,806. A motor drives an eccentric shaft which moves a carriage with crimping tools up and down. An encoder driven by means of the motor shaft serves for positional determination of the crimping tool. The crimp contact to be connected with a conductor end lies on a stationary anvil, wherein lugs of the crimp contact are plastically deformed on downward movement of the crimping tool and produce the connection to the conductor. The position of the crimping tool in the crimping region is measured by means of a height sensor, wherein the sensor signal is used independently of the encoder signal. At the same time the crimping force is measured on the basis of the motor current. The measurement values are compared with reference values. The comparison enables a statement about the crimp quality.
Although an encoder and a height sensor are present, only a relatively imprecise statement about the crimp quality can be made, because external influences as well as the degree of elasticity or rigidity of the mechanical driven elements are not taken into consideration.
The present invention avoids the disadvantages of the known equipment and is accordingly directed to a method and apparatus in which the crimp quality of a crimped connection can be improved.
The advantages achieved by the invention are essentially to be seen in that alteration of the crimping press is not necessary for processing different crimp contacts by different tool strokes. The crimping height and the crimping stroke are adjustable. Moreover, the crimping press control recognizes the exact tool position each time the press is activated, whereby a simple evaluation of the crimping force versus crimping stroke can be made and other machines participating in the crimping process can be synchronized.
The crimping press according to the invention operates with two measuring systems, by means of which a regulation of the drive with respect to position or crimping height regulation can be obtained. A rotative measuring system is coupled with a linear measuring system. The rotative measuring system enables a high positioning dynamic, because no dead times, caused by play in gears, levers or slides, are present. The linear measuring system enables precise crimp height regulation. Mechanically-caused tolerances of the crimping press, which may be due to, for example, crimping force or temperature fluctuations, are compensated for by the crimp height regulation. With the crimp height regulation the eccentric of the crimping press moves an angular range between 0xc2x0 and 180xc2x0 as limits. The crimping press stops at the lower dead center and subsequently reverses. Upper and lower dead center positions can be moved to as desired within the 0xc2x0-180xc2x0 angular range according to the respective crimping tool and crimp contact utilized. Intermediate stop positions are also possible. For realization of this feature only a regulated axis is necessary, and the carriage stroke or crimping height can be programmed. Moreover, the course of the crimping force as a function of the crimping stroke can be represented exactly and is usable for quality control purposes.